> ccTLDs are two-letter (exceptions apply)

ccTLDs are two letters by definition. Other geographic TLDs like .cat, .wales, or .london are not ccTLDs.

.gov, .mil, and .edu are not considered ccTLDs or gTLDs. They're technically in another category entirely: "sponsored TLDs".

> First: use only a registrar listed on ICANN […] Second: are your registrar accredited by the specific registry?

Both of these are guaranteed to be true by the governance structure of gTLD domain registries -- a gTLD registry cannot provide services to registrars which don't have accreditation.

> Domain resellers (without ICANN accreditation) go bust nearly everyday and recourse is hard if you decide to go to a reseller

This is not true. Resellers can "go bust", but the registrar of record (that is, the "real" registrar that's being resold) has the customer's contact information and can continue to offer registration services. In fact, they're obligated to do so.